1. Field of Invention
This invention relates to a gantry pallet for, but not limited to, transporting, storing and protecting the U.S. Navy's, steam tube gantry crane. The steam tube gantry crane is designed to reposition by rising and lowering an aircraft carrier's catapult steam tube; a critical component of the launch process, as it is removed, overhauled and replaced by manufacturing artisans.
2. Summary
A conventional catapult steam tube removal team consists of one crane and operator, one forklift and operator, a minimum of 30 men, numerous nylon slings, wooden pallets, dunnage, torque wrenches and approximately twelve foot on either side of the launch trough steam tube for maneuvering. Numerous person-hours are required to both set-up to remove or to replace the steam tubes. The aircraft carrier's catapult steam tube assembly is required to be either lowered or lifted evenly to prevent damage to the steam tube seals. The steam tubes are assembled in twelve-foot sections spanning the length of the Aircraft carrier's deck.
Post disassembly from the aircraft carriers steam system and post removal from within the aircraft carriers launch trough, the steam tube gantry cranes are individually removed from a storage area that is approximately 4,000 sf. The gantry crane appurtenances: chains, wrenches, fastening devices and torque wrenches are removed from a separate twenty-foot long container, stacked on pallets, individually raised and set upon the ship. Seamen center the steam tube gantry crane's hoisting cable over the steam tube prior to the gantry crane's cable attaching to the steam tube.
Once the gantry cranes are attached to the steam tube, the Seamen mount the gantry crane, attach the cable wench handles and wind up the cable to a prescribe tension. After all the gantry cranes cables are in tension one seaman sounds a whistle and at the sounding each of the 30 seamen rotates his gantry crane's wench one revolution. This sounding and wench rotation is repeated until the entire length of the aircraft carrier's catapult steam tube assembly is raised out of the catapult launch trough. After the steam tubes are removed from the catapult steam trough, gantry cables disconnected and the twelve-foot sections are palletized and removed the gantry cranes are individually moved away from the catapult steam trough, lowered off the ship and stored outside. The gantry crane appurtenances are then gathered, returned to a pallet and offloaded to a waiting twenty-foot long container.
It is not only during on and off loading that damage occurs to the gantry cranes but also during transportation to the storage area. Because the gantry cranes are top heavy, they easily topple over and sustain damage to their stainless steel cables and to the gears that operate the wench. Because the gantry cranes are stored outside, they are not protected from the elements and frequently sustain rain damage as well as lubrication contamination from wind borne debris such as dirt and dust. While the wench portion of the gantry crane can be covered, the covers often are blown off during periods of high wind resulting in water damage. These covers, once separated from the gantry crane are often lost, stored in a non-descript place or used as parts bags for the gantry cranes appurtenances such as nuts and bolts. Approximately 4,000 square foot of area is needed to store the gantry cranes and a twenty-foot long by eight-foot wide container is required to store the accompanying appurtenances. Once dockside, at the aircraft carriers edge, the time required to gather the gantry cranes, appurtenances and on-load them is 12 hours. Post repairing the catapults steam tube the entire process of on and off loading of the gantry cranes is repeated. The current methodology of loading the gantry cranes on and off and that of the gantry crane storage is both time consuming and damaging to the gantry cranes.
3. Prior Art
While there exist devices such as but not limited to U.S. Pat. Nos. 2,828,931 & 7,131,803, they all have similar deficiencies. Particularly '931 lacks a storage locker for the storage of small nuts and bolts, and the underside of '931 does not have a no-marring surface so it would mar and damage an aircraft carriers deck, also '931 is neither stackable when use as described nor is '931 able to create a weather tight seal when used as described. Similarly, '803 contains many of the same deficiency, no storage locker for storage of small nuts and bolts, underside of frame is marring and thus damaging to an aircraft carriers deck when used as described and there does not exist a structure for making a weather tight seal to protect the contents of '803. Noted are the single directional fork pockets on '931 and '803; this allows forklift loading in one direction, which is a deficiency. Also, neither '931 nor '803 contain self-closing access panels for quick access to stored components. Additional deficiencies found in both '931 and '803 are neither contains a tie-down for use on an aircraft carrier flight deck nor does '931 or '803 have a single crane lifting lug. Without a tie down specifically designed to attach '931 or '803 to said deck, said '931 and '803 become projectiles sliding around said deck during rough seas. The lack of a single crane lift lug implies that many slings or connections must be made to lift and move '931 or '803 without a forklift. As cited, neither '931 nor '803 are particularly suited for use on an aircraft carrier as a device to transport, store, or shield from moisture said gantry cranes.
Using my invention a removal team, such as but not limited to, an aircraft carriers catapult's steam tube removal team will no longer need the many machines and operators once required. The removal team can now load 30 gantry cranes in six lifts. Because of the built in upper and lower appurtenance storage locker(s) the searching for lost bolts or tools will be eliminated, each pallet of cranes will have the appurtenances needed moved along with the gantry cranes and be within easy reach.
My invention, primarily for but not limited to, an aircraft carriers catapult steam tube gantry crane is also used to protect the gantry crane from the elements, thus limiting the damage caused from rain and dirt, lengthening the time interval between gantry crane overhaul and prolonging the service life of the gantry crane.
My invention's mounting plates settle the gantry crane directly into a tie-down after removal from the aircraft carriers launch trough negating the opportunity to further damage the gantry crane and the aircraft carrier flight deck from human error during the removal and loading process. The design used to tie-down the gantry crane immobilizes the gantry crane during shipping, and virtually eliminates shifting during transportation.
My invention has fork lifting pockets incorporated into structural steel base frame, a corrosion resistant, ridged shipping cover that protects the object, such as but not limited to, the U.S. Navy's steam tube gantry cranes. Additionally, said cover has a moisture barrier reservoir vent filter breather and a gasket to seal the cover at the underside perimeter where said cover contacts the base frame.
Another advantage of the present invention is amount of space saved when the gantry cranes are stored. Because the gantry pallet can be vertically stacked, the footprint of 30 gantry cranes' in my gantry pallets is greatly reduced.